hwmon: (it87) Add support for the ITE IT8720F

Allow it87.c to handle IT8720 chipset like IT8718 in order to
retrieve voltage, temperatures and fans speed from sensors
tools. Also updating the related documentation.

Signed-off-by: Jean-Marc Spaggiari <jean-marc@spaggiari.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 1ef1205..aba01b4 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -400,7 +400,8 @@
 	select HWMON_VID
 	help
 	  If you say yes here you get support for ITE IT8705F, IT8712F,
-	  IT8716F, IT8718F and IT8726F sensor chips, and the SiS960 clone.
+	  IT8716F, IT8718F, IT8720F and IT8726F sensor chips, and the
+	  SiS960 clone.
 
 	  This driver can also be built as a module.  If so, the module
 	  will be called it87.